Fans of '60's music, my 14-year-old daughter and her best friend got front-row tickets to a Peter, Paul, and Mary concert.

When they returned home, my daughter said, "During the show, we looked back an saw hundreds of little lights swaying to the music. At first we thought people were holding up cigarette lighters. Then we realized that the lights were the reflections off all the eyeglasses in the audience.